Java.util.zip.InflaterInputStream class in Java

Last Updated : 12 Sep, 2023

This class implements a stream filter for uncompressing data in the "deflate" compression format. It is also used as the basis for other decompression filters, such as GZIPInputStream. Constructors

InflaterInputStream(InputStream in) : Creates a new input stream with a default decompressor and buffer size.
InflaterInputStream(InputStream in, Inflater inf) : Creates a new input stream with the specified decompressor and a default buffer size.
InflaterInputStream(InputStream in, Inflater inf, int size) : Creates a new input stream with the specified decompressor and buffer size.

Methods:

int available() : Returns 0 after EOF has been reached, otherwise always return 1.

Syntax : public int available()
              throws IOException
Returns:
1 before EOF and 0 after EOF.
Throws:
IOException

void close() : Closes this input stream and releases any system resources associated with the stream.
```
Syntax : public void close()
           throws IOException
Throws:
IOException 
```

protected void fill() : Fills input buffer with more data to decompress.

Syntax : protected void fill()
             throws IOException
Throws:
IOException

void mark(int readlimit) : Marks the current position in this input stream.

Syntax : public void mark(int readlimit)
Parameters:
readlimit - the maximum limit of bytes that can be read
before the mark position becomes invalid.

boolean markSupported() : Tests if this input stream supports the mark and reset methods.

Syntax : public boolean markSupported()
Returns:
a boolean indicating if this stream type supports the mark and reset methods.

int read() : Reads a byte of uncompressed data.

Syntax : public int read()
         throws IOException
Returns:
the byte read, or -1 if end of compressed input is reached
Throws:
IOException

int read(byte[] b, int off, int len) : Reads uncompressed data into an array of bytes.

Syntax : public int read(byte[] b,
       int off,
       int len)
         throws IOException
Parameters:
b - the buffer into which the data is read
off - the start offset in the destination array b
len - the maximum number of bytes read
Returns:
the actual number of bytes read, or -1 if the end of the compressed input is reached.
Throws:
NullPointerException 
IndexOutOfBoundsException 
ZipException
IOException

void reset() : Repositions this stream to the position at the time the mark method was last called on this input stream.
```
Syntax : public void reset()
           throws IOException
Throws:
IOException
```

long skip(long n) : Skips specified number of bytes of uncompressed data.

Syntax : public long skip(long n)
          throws IOException
Parameters:
n - the number of bytes to skip
Returns:
the actual number of bytes skipped.
Throws:
IOException 
IllegalArgumentException

Program:

Java

//Java program to demonstrate InflaterInputStream
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.InflaterInputStream;


class InflaterInputStreamDemo
{
    public static void main(String[] args) throws IOException
    {

        FileOutputStream fos = new FileOutputStream("file.txt");

        //Assign FileOutputStream to DeflaterOutputStream
        DeflaterOutputStream dos = new DeflaterOutputStream(fos);

        //write it into DeflaterOutputStream
        for (int i = 0; i < 10; i++)
        {
            dos.write(i);
        }
        dos.flush();
        dos.close();
        FileInputStream fis = new FileInputStream("file.txt");
        InflaterInputStream iis = new InflaterInputStream(fis);

        //illustrating available() method
        System.out.println(iis.available());

        //illustrating mark and markSupported()
        if (iis.markSupported())
            iis.mark(15);
        else
            System.out.println(false);
        
        //illustrating skip() method
        iis.skip(3);

        //illustrating read()
        for (int i = 0; i <3 ; i++) 
        {
            System.out.print(iis.read());
        }

        //illustrating read(byte[] b,int off,int len)
        byte b[]=new byte[4];
        
        for (int i = 0; i <4 ; i++) 
        {
            iis.read(b,0,4);
        }
        
        for (int i = 0; i < 4; i++) 
        {
            System.out.print(b[i]);
        }
    }
}